1. Field of the Invention
The present invention relates to a disk array device, and particularly relates to a disk array device having a function for degrading a structural component.
2. Description of the Related Art
Unexamined Japanese Patent Application KOKAI Publication No. H11-194898 discloses a disk array device. This disk array device retries a processing (reading and wiring) toward a disk device when the processing is finished in an abnormal state. If the disk array device succeeds in the retrial, it continues the use of the disk device, while if the disk array device fails in the retrial, it degrades (separates) the disk device.
According to this conventional disk array device, in a case where although frequently finished in an abnormal state, a processing can be properly executed if it is retried, the processing target disk device can not be degraded. In this case, since responses to a host device from the disk array device are delayed, processes at the host device in an online operation are delayed, possibly causing troubles in the execution of the operation.
Further, according to this disk array device, if a state where a processing, though can be finished properly, requires a long time to be executed continues, responses to a host device from the disk array device are delayed, causing delay in processes at the host device.
Further, according to this disk device, if a processing is finished in an abnormal state or a processing time increases, the processing performance of the overall disk array device drops. As a result, responses to a host device from the disk array device are delayed, causing delay in processes at the host device.
The above-described problems occur in other structural components (for example, a memory and an MPU (Micro Processor Unit)) than the disk device.